Expansion valve

ABSTRACT

The invention relates to an expansion valve ( 10 ), for controlling a fluid flow, having a valve means housing ( 12 ) and at least one valve means ( 16 ), which is movably arranged in a valve means housing ( 12 ), and an actuator housing ( 14 ), in which the electrical drive of the expansion valve ( 10 ) is arranged, wherein the valve means housing ( 12 ) is formed substantially at least in part of a metal, in particular of aluminum, and wherein the actuator housing ( 14 ) is formed substantially at least in part of plastic and wherein the actuator housing ( 14 ) is secured on the valve means housing ( 12 ) by means of at least one connection element ( 40 ). According to the invention, the connection element ( 40 ) is formed at least in part as a latching element and/or clip element.

BACKGROUND OF THE INVENTION

The invention is based on an expansion valve.

It is already known to arrange an actuator housing on a valve meanshousing in an expansion valve by means of a screw connection. Such aconnection is however subject to a plurality of space-inducedrestrictions.

The invention is based on an expansion valve for controlling a fluidflow, having a valve means housing and at least one valve means which ismovably arranged in the valve means housing, and an actuator housing inwhich the electric drive of the expansion valve is arranged, wherein thevalve means housing is substantially formed at least partly of a metal,in particular of aluminum, and wherein the actuator housing issubstantially formed at least partly of plastic, and wherein theactuator housing is secured on the valve means housing by means of atleast one connecting element. It is proposed that the connecting elementis formed at least partly as a latching element and additionally oralternatively as a clip element.

SUMMARY OF THE INVENTION

The expansion valve according to the invention has the advantage that asimple and economic connection can be established between the actuatorhousing and the valve means housing. The actuator housing can be mountedon the valve means housing particularly easily by means of theconnecting element according to the invention. Furthermore, theinstallation space necessary for the connection may be reduced. Theconnecting element according to the invention here allows a connectionof different expansion valve variants without additional adaptation. Theconnecting element according to the invention is here advantageouslyable to provide a simple and secure connection between two components ofdifferent materials.

In an expansion valve of the type concerned here, the fluid is at leastpartially present in a gaseous phase in the through-flow region of thevalve means housing, wherein high pressures may prevail in the rangebetween 1-30 bar and briefly up to 100 bar. Because of thesethermodynamic peripheral conditions, such a valve means block is made ofa metal, preferably aluminum or an aluminum alloy. It is however alsoconceivable that at least one housing part of the valve means housinghas a plastic body with a diffusion-inhibiting barrier layer containingmetal. Such a valve means housing can be produced simply andeconomically in comparison with an aluminum block housing. At the sametime, because of the gas-tightness of the expansion valve according tothe invention, it may be used in fluid circuits in which the fluid is atleast partially present in a gaseous phase. The actuator housing inwhich the electric drive is arranged is subjected to differentperipheral conditions with respect to tightness and functionality, sothat this is made at least partially of plastic.

A fluid of the type concerned here is a heat transfer medium whichcirculates within the fluid circuit. In particular, the fluid is anatural refrigerant, such as for example hydrocarbons, carbon dioxide,ammonia, propane, butane, propylene, water, or a synthetic refrigerantsuch as for example fluorochlorohydrocarbons or partly halogenatedfluorochlorohydrocarbons.

The measures outlined in the subclaims give advantageous refinements andimprovements of the independent features.

An advantageous refinement of the invention proposes that the connectingelement has at least a first portion and at least a second portion,wherein the first portion at least partly engages in the valve meanshousing, and wherein the second portion at least in portions latches tothe actuator housing, and wherein the second portion has a firtree-liketoothing on its outer casing surface.

In the context of the present invention, a firtree-like toothing meansan outer contour of the connecting element which has a plurality ofteeth. The teeth or protrusions of the firtree-like toothingadvantageously latch or catch in the receiver on the actuator housing,so that a particularly simple and secure connection of the housing canbe provided. Because the actuator housing is made of plastic, theactuator housing deforms on insertion of the firtree-like toothing sothat a captive connection can be provided.

According to an advantageous refinement of the invention, it is providedthat the first portion of the connecting element is configured so as tobe elastic in the circumferential direction. Such a connecting elementwhich is elastic in the circumferential direction may be introducedparticularly easily into the valve means housing under pretension, sothat the connecting element is held in the housing because of the returnforce. A particularly simple and robust solution may be provided if thefirst portion is formed as an at least partly slotted sleeve.

According to an advantageous refinement of the invention, the secondportion extends substantially in the axial direction, wherein the secondportion is configured so as to be substantially flat and has an inletchamfer on its free end facing away from the first portion. Such aninlet chamfer allows particularly simple insertion of the second portionin the actuator housing. In the context of the present invention, theaxial direction of such an expansion valve means in particular theextent direction of the valve shaft on which the valve means isarranged.

According to an advantageous refinement of the invention, the connectingelement engages around the valve means housing and the actuator housingin the axial direction. Preferably, here the connecting element isconfigured as a clamping element. By means of such a clamping elementapplied under pretension, a particularly simple and compact connectioncan be created between the actuator housing and the valve means housing.

A particularly simple and compact connecting element may be provided inparticular if the connecting element is configured so as to besubstantially U-shaped and has at least two legs, wherein the legs arearranged substantially parallel to one another. Preferably, the legs ofthe connecting element furthermore each have a free end, whereinclamping protrusions are arranged on each free end of the connectingelement. In mounted state, these clamping protrusions may engage incorresponding undercuts which are provided on the valve means housingand alternatively or additionally also on the actuator housing.

A particularly economic connecting element may be provided in particularif the connecting element is configured as one piece, in particular as apunched bent part.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings depict exemplary embodiments of the expansion valve andconnecting element which are explained in more detail in the descriptionwhich follows. The drawings show:

FIG. 1 a perspective, exploded illustration of an expansion valveaccording to a first embodiment,

FIG. 2 a perspective illustration of a connecting element configured asa clamping element,

FIG. 3 a perspective illustration of a valve means housing andconnecting elements arranged on the valve means housing,

FIG. 4 a perspective illustration of a connecting element according tothe embodiment shown in FIG. 3.

DETAILED DESCRIPTION

In the various embodiment variants, the same parts carry the samereference signs.

FIG. 1 shows a first exemplary embodiment of an expansion valve 10 in anexploded illustration. As can be clearly seen in FIG. 1, the expansionvalve 10 comprises an actuator housing 14 and a valve means housing orvalve housing 12. At least one valve means or valve member 16 isarranged inside the valve means housing 12. The valve means 16 isconfigured so as to be movable, in particular rotatable relative to thevalve means housing 16. Furthermore, the first valve means housing 12has a through-flow region through which a fluid flows. A fluid of thetype concerned here is a heat transfer medium which circulates withinthe fluid circuit. In particular, the fluid is a natural refrigerant,such as for example hydrocarbons, carbon dioxide, ammonia, propane,butane, propylene, water, or a synthetic refrigerant such as for examplefluorochlorohydrocarbons or partly halogenated fluorochlorohydrocarbons.

The valve means housing 12 has at least two first openings 20, 22 whichform an inlet and an outlet respectively for the fluid in the valvemeans housing 12. Because of the view selected, FIG. 1 shows only one ofthe two first openings 20, 22. In the embodiment of the invention shownin FIG. 1, the two openings 20, 22 are arranged inside the valve meanshousing 12 perpendicularly to an axial direction 18 of the expansionvalve 10. The valve means housing 12 may in particular be configured asa valve means block which is configured so as to be substantiallygas-tight under the thermodynamic conditions present in an expansionvalve 10.

In an expansion valve 10 of the type concerned here, the fluid is atleast partially present in a gaseous phase in the through-flow region ofthe valve means housing 12, wherein high pressures may prevail in therange between 1-30 bar and briefly up to 100 bar. Because of thesethermodynamic peripheral conditions, such a valve means block 12 is madeof a metal, preferably aluminum or an aluminum alloy. It is however alsoconceivable that at least one housing part of the valve means housing 12has a plastic body with a diffusion-inhibiting barrier layer containingmetal. Such a valve means housing 12 can be produced simply andeconomically in comparison with an aluminum block housing. At the sametime, because of the gas-tightness of the expansion valve 10 accordingto the invention, it may be used in fluid circuits in which the fluid isat least partially present in a gaseous phase.

As FIG. 1 shows, an actuator housing 14 is arranged on the valve meanshousing 12. According to the embodiment of the invention shown in FIG.1, the actuator housing 14 comprises two actuator housing parts 24, 26,inside which an electric drive (not shown here) is arranged. Such anelectric drive may be configured in particular as a stepper motor, abrushless motor or a brush motor. The actuator housing 14 is formedsubstantially at least partly of plastic. In particular, the actuatorhousing 14 is produced by means of injection molding processes.

As well as the electric drive, according to an advantageous embodimentof the invention, a gear mechanism is arranged inside the actuatorhousing 14 which transmits the motion of the electric drive to acorresponding valve shaft 30. Furthermore, the actuator housing 14contains motor electronics for controlling the electric drive. Thecorresponding valve means is arranged on the valve shaft 30. The valveshaft 30 passes through an opening 32 of the valve means housing 12 andextends substantially in the axial direction 18.

To seal the through-flow region of the fluid, a housing element 34formed as a cover is arranged on the second opening 32. The housingelement 34 here has a bore which is concentric to the axial direction 18and through which the valve shaft 30 protrudes into the valve meanshousing 12.

According to the invention, it is now provided that the actuator housing14 is secured to the valve means housing 14 by means of at least oneconnecting element 40, which is configured at least partly as a latchingelement and alternatively or additionally as a clip element. FIGS. 1 and2 each show a first embodiment of such a latching or clip element.

As FIG. 1 shows, the connecting element 40 according to the embodimentof the invention shown here engages around the valve means housing 12and the actuator housing 14 in the axial direction 18, and is configuredas a clamping element. At one of its free ends 42 b, the clampingelement 40 has a clamping protrusion 44, and a further clampingprotrusion 45 is formed by the arcuate segment 60. Preferably, thearcuate segment is part of the free end 42 a, in particular the leg 58.The clamping protrusions 44, 45 engage in corresponding undercuts 46, 47of the valve means housing 12 or actuator housing 14.

According to the embodiment of the invention shown in FIG. 1, theundercut 46 of the valve means housing 12 is configured as a recess inthe valve means housing 12, extending substantially in the radialdirection. Preferably, the side face 48 of the undercut 46 facing theactuator housing 14 extends substantially perpendicularly to the axialdirection 18. This side face 48 in mounted state acts as an axial stopfor the connecting element 40.

According to the embodiment of the invention shown in FIG. 1, at leastone radially extending protrusion 50 is arranged on the actuator housing14, and the undercut 47 of the actuator housing 14 is at least partlyformed on said protrusion. On mounting of the connecting element 40,usually firstly the first clamping protrusion 44 is placed in theundercut 46 of the valve means housing 12, and then the second clampingprotrusion 45 is inserted into the corresponding undercut 47 of theactuator housing 14. In order to facilitate the insertion or pressing ofthe second clamping protrusion 45 into the undercut 47 on the actuatorhousing 14, the protrusion 50 of the actuator housing 14 preferably hasan inlet chamfer 52.

According to the embodiment of the invention shown in FIG. 1, theexpansion valve 10 has two connecting elements 40 which are arranged onopposite sides of the expansion valve 10. Evidently however, the numberand arrangement of the connecting elements 40 may vary.

FIG. 2 shows the connecting element 40 from FIG. 1 in enlarged scale.According to the embodiment of the invention shown in FIG. 2, clampingelement 40 is configured so as to be substantially U-shaped, having afirst middle portion 56 and legs 58, 59 which are arranged on eitherside of the middle portion 56 and each form the free ends 42 a, b of theconnecting element 40. According to the embodiment of the inventionshown in FIG. 2, the legs 58, 59 of the clamping element 40 are arrangedsubstantially parallel to one another and in mounted state extendsubstantially in the radial direction. In the embodiment shown in FIG.2, the middle portion 56 of the clamping element 40 is formed flat atleast in portions, and in mounted state extends substantially in theaxial direction 18.

The clamping element 40 with its legs 58, 59 spans the edge regionbetween the mutually abutting valve means housing 12 and actuatorhousing 14. As already explained, the clamping element comprisesclamping protrusions 44, 45, which in mounted state engage in therespective undercuts 46, 47 on the valve means housing 12 and actuatorhousing 14. The clamping protrusion 45, which in mounted state engagesin the actuator housing 14, is bent by an acute angle β with respect tothe extent direction of the assigned leg 58. Suitably, the clampingprotrusion 45 has an arcuate segment 60 extending in the axial direction18, which on mounting slides over the inlet chamfer 52 before engagingin the corresponding undercut 47. The leg 59, which in mounted stateengages in the valve means housing 12, is designed so as to besubstantially arcuate, wherein in mounted state, the free end 42 b ofthe arcuate leg 59 bears on the side wall 48 of the undercut 46 of thevalve means housing 12. In this way, on mounting, an adequate pretensioncan be applied to the clamping element 40.

The connecting element 40 shown in FIG. 2 is configured as one piece.Such a connecting element 40 can be produced particularly easily bymeans of punching-bending processes.

The free end 42 b of the clamping element 40 forms the clampingprotrusion 44.

According to an advantageous refinement, the clamping element 40 has abend over its width in the region 49. Optionally, a bend is also formedover the width in the middle portion 56. The optional bend in the region49 is preferably reversed with respect to the optional bend in theregion 56.

The end faces 51 of the free ends 42 a, b have edges and/or cornerswhich are preferably not rounded or angled. At the end faces 51, thefree ends 42 a, b are formed with edges and/or corners. There is notapering towards the free ends 42 a, b. The clamping protrusion 44 andthe free end 42 b have no taper in width. The clamping protrusion 44 andthe free end 42 b have edges and/or corners. The clamping protrusion 44and the free end 42 b preferably have no roundings.

The end faces 51 of the free ends 42 a, b are formed rectangular.Preferably, the edges are sharp and not rounded.

Preferably, the width of the clamping element 40 is substantiallyconstant over its entire length.

According to an advantageous refinement, the end face 51 of the free end42 b forming the clamping protrusion 44 has a concave course over itswidth. The two opposing edges of the end face 51 of the free end 42 b,which do not point towards the middle portion 56, protrude beyond themiddle in the axial direction. Preferably, in mounted state, the edgesengage first in the undercut 46. This prevents for example a shifting ofthe clamping element 40 with respect to the actuator housing 14 alongthe undercut 46.

Preferably, the middle portion 56 has no kink in the axial direction.

The free end 42 b forms the clamping protrusion 44. A further clampingprotrusion 45 is formed by the leg 58 or the further free end 42 a, inparticular the arcuate segment 60.

The normal vector of the end face 51 of the free end 52 b pointssubstantially in the axial direction 18.

FIGS. 3 and 4 each show a second embodiment of a connecting element 40.FIG. 3 shows a perspective illustration of the valve means housing 12 ofthe expansion valve 10. As clearly evident in FIG. 3, the valve blockhas at least two first openings 20, 22 through which the fluid may flowin and out. Furthermore, the valve means housing 12 has a second opening32 through which the valve shaft 30 passes. The valve means housing 12has a substantially flat contact face 35 on which the actuator housing14 is arranged in mounted state.

As clearly evident from FIG. 3, the connecting element 40 has at least afirst portion 70 and a second portion 72 for connecting the valve meanshousing 12 to the actuator housing 14. The first portion 70 here atleast partly engages in a corresponding bore 80 of the valve meanshousing 12. The second portion 72 on its outer casing surface has afirtree-like toothing 74. As clearly evident from FIG. 2, the secondportion 72 of the connecting element 40 extends substantially in theaxial direction 18. The first portion 70 of the connecting element 40 isconfigured so as to be elastic in the circumferential direction, and isheld in the valve means housing 12 because of its spring force andfriction. On mounting of the actuator housing 14, the second portion 72with its firtree-like toothing 74 engages in the actuator housing 14 andlatches or catches there, which allows a secure connection between thevalve means housing 12 and the actuator housing 14.

According to the embodiment of the invention shown in FIG. 3, forconnecting the actuator housing 14 to the valve means housing 12, twoconnecting elements 40 are provided, wherein the two connecting elements40 are arranged twisted by 45° relative to one another in thecircumferential direction.

Evidently however, the number and arrangement of the connecting elements40 may vary.

FIG. 4 shows in enlarged scale a connecting element according to theembodiment shown in FIG. 3. As clearly evident from FIG. 4, theconnecting element 40 has a first portion 70 and a second portion 72.The connecting element 40 extends substantially in the axial direction18. In mounted state, the first portion 70 engages at least partly inthe valve means housing 12, and the firtree-like toothing 74 arranged onthe outer casing surface of the second portion 72 latches into theactuator housing 14. As already stated, the first portion 70 isconfigured so as to be elastic in the circumferential direction.According to the embodiment of the invention shown in FIG. 4, the secondportion 70 is to this end configured as a slotted sleeve.

As shown in FIG. 4, both the slot 88 and the passage opening 90 of theslotted sleeve 70 here extend substantially in the axial direction 18.On mounting, the slotted sleeve 70 is compressed and inserted in thebore 80 of the valve means housing 12 extending in the axial direction18. Because of the return force of the elastic sleeve, it is pressedagainst the bore wall of the valve means housing 12 and held there.

As is clearly evident from FIG. 4, the second portion 72 is arranged onan end face 92 of the sleeve 70. Preferably, the second portion 72 liesradially opposite the slot 88. The second portion 72 extendssubstantially in the axial direction 18 and is formed so as to besubstantially flat. On its outer casing surface, it has the firtree-liketoothing 74. According to the embodiment of the invention shown in FIG.4, the firtree-like toothing is formed by three teeth 74 arranged oneach side of the second portion. Preferably, the tooth size of the teeth94 diminishes with decreasing distance from the first portion 70. Asclearly evident in FIG. 4, at its free end facing away from the firstportion, the second portion 72 has an inlet chamfer 96 which facilitatesmounting of the actuator housing 14 on the valve means housing 12. Theconnecting element 40 shown in FIG. 4 is configured as one piece. Such aconnecting element 40 can be produced particularly easily by means ofpunching-bending processes.

1. An expansion valve (10) for controlling a fluid flow, having a valvehousing (12) and at least one valve member (16) which is movablyarranged in the valve housing (12), and an actuator housing (14)configured to house an electric drive of the expansion valve (10),wherein the valve housing (12) is substantially formed at least partlyof a metal, and wherein the actuator housing (14) is substantiallyformed at least partly of plastic, and wherein the actuator housing (14)is secured on the valve housing (12) by at least one connecting element(40) formed at least partly as a latching element and/or clip element.2. The expansion valve (10) as claimed in claim 1, characterized in thatthe connecting element (40) has at least a first portion (70) and asecond portion (72), wherein the first portion (70) at least partlyengages in the valve housing (12), and wherein the second portion (72)at least in portions latches to the actuator housing (14), and whereinthe second portion (72) has a firtree-like toothing (74) on an outercasing surface of the second portion.
 3. The expansion valve (10) asclaimed in claim 2, characterized in that the first portion (70) of theconnecting element (40) is configured so as to be elastic in acircumferential direction.
 4. The expansion valve (10) as claimed inclaim 2, characterized in that the second portion (72) extendssubstantially in an axial direction (18), wherein the second portion(72) is configured so as to be substantially flat and has an inletchamfer (96) on a free end facing away from the first portion (70). 5.The expansion valve (10) as claimed in claim 1, characterized in thatthe connecting element (40) engages around the valve housing (12) andthe actuator housing (14) in an axial direction (18).
 6. The expansionvalve (10) as claimed in claim 1, characterized in that the connectingelement (40) is configured so as to be substantially U-shaped and has atleast two legs (58, 59), wherein the legs (58, 59) are arrangedsubstantially parallel to one another.
 7. The expansion valve (10) asclaimed in claim 6, characterized in that the legs (58, 59) of theconnecting element (40) each have a free end (42 a, b), wherein clampingprotrusions (44, 45) are arranged on each free end (42 a, b) of theconnecting element (40).
 8. The expansion valve (10) as claimed in claim7, characterized in that an undercut (46, 47), in which thecorresponding clamping protrusion (44, 45) of the connecting element(40) engages, is arranged on the valve housing (12) and/or the actuatorhousing (14).
 9. The expansion valve (10) as claimed in claim 1,characterized in that the connecting element (40) is configured as onepiece.
 10. The expansion valve (10) as claimed in claim 1, characterizedin that the valve housing (12) has at least two first openings (20, 22),wherein the valve member (16) is movably arranged inside the valvehousing (12), and a fluid flow through the openings (20, 22) isdefinable and changeable depending on the position of the valve member(16) with respect to the openings (20, 22).
 11. The expansion valve (10)as claimed in claim 10, wherein the valve member (16) is configured tobe moved by the electric drive.
 12. The expansion valve (10) as claimedin claim 1, wherein the valve housing (12) is substantially formed atleast partly of aluminum.
 13. The expansion valve (10) as claimed inclaim 2, characterized in that the first portion (70) of the connectingelement (40) is configured so as to be elastic in a circumferentialdirection as an at least partly slotted sleeve.
 14. The expansion valve(10) as claimed in claim 1, characterized in that the connecting element(40) engages around the valve housing (12) and the actuator housing (14)in an axial direction (18), wherein the connecting element (40) isconfigured as a clamping element.
 15. The expansion valve (10) asclaimed in claim 1, characterized in that the connecting element (40) isconfigured as one piece as a punched bent part.